Ideally, a company will have growing revenue and growing profits. But even good companies can have a year or two in the red — perhaps because they're spending heavily on advertising or on growth, or because they're facing a temporary setback. And younger, smaller companies may run many losses in their early years. So unprofitability isn't necessarily a deal-breaker, but it's best to focus your dollars on companies that are reliably profitable. With any possible investment, study its financial reports: Check whether it's gaining or losing market share, how strong its competitive advantages are, and whether its future seems promising. Q: Can you recommend any investing guides for beginners? — J.S., Bixby, Okla.